A vanload of undergraduates on a weekend camping trip runs across the path of 40-ish lifelong best pals Tucker (Alan Tudyk) and Dale (Tyler Labine). Tucker and Dale try not to ogle the party’s gorgeous, scantily clad girls, while the youths automatically assume these “hillbillies” are probably just a half-rung up the evolutionary ladder from “The Hills Have Eyes.”

When frat brat Chad (Jesse Moss) later comes on to Allison (Katrina Bowden), she storms off in a huff and winds up nearly drowning. The not-quite-local yokels — Tucker and Dale are just fixing up a nearby old shack as vacation home — save her. But the undergrads assume the two have kidnapped Allyto perform God-knows-what unnatural acts.

An initially oblivious Ally (a farm gal herself) bonds with Tucker and Dale, who took her home out of genuine concern, even as noxious Chad turns into a frothing junior Rambo in polo shirt (collar turned up, natch). He’ll rescue her even if he has to kill her doing it.

As misunderstandings escalate, the youths in their haplessness and panic accidentally off themselves, or one another with alarming regularity — with each incident interpreted as further evidence of the rednecks’bloodlust. Labine and Tudyk have terrific comedic chemistry as the down-home, very nice and not-so-dumb heroes. The co-creators have given them some bright lines (and others were apparently improvised by the thesps). But once the pic whips itself up to a fine frenzy around the midpoint, there’s a bit of a lull, and later action doesn’t quite match the inspired lunacy of the early reels.

Still, “Tucker & Dale” is more than promising as a first feature — it’s assured in every department, from comic timing to widescreen HD lensing to other polished design/tech contributions on a low budget.

Though set in West Virginia’s Appalachians, the film was actually shot in Alberta, just outside Calgary.